Field of the Invention
The invention relates to elevators, elevator installation and a method and an apparatus for automatic elevator drive configuration.
Description of the Related Art
An important part of elevator installation is the configuration of the elevator drive. The elevator drive controls power supply to an electrical motor and brakes of the elevator and thus affects the lifting regarding, for example, acceleration, deceleration, speed and height lifted or lowered.
The elevator drive must be configured appropriately following installation of elevator roping, counterweight and elevator car in an elevator shaft to ensure safe, comfortable and correct operation of the elevator. The configuration of the elevator drive comprises specifying a number of parameters to be stored in a memory associated with the elevator drive. Some of the parameters are associated with properties of the elevator electrical motor such as nominal torque, nominal current, source voltage, input frequency and acceleration current, whereas some of the parameters are associated with the elevator generally such as roping ratio and weights of the elevator car and the counterweight. Among the parameters associated with the motor are also parameters related to integral parts of the motor such as traction sheave and brakes. Regarding the traction sheave it is important to know the diameter of the traction sheave so that supplying frequency of the motor and torque to be applied to the ropes by the motor may be determined. Regarding the brakes it is important to know the current and voltage to be supplied to the brakes to keep the brakes open and the time it takes to apply the brakes.
In prior art the configuration of elevator drive has been performed using a user interface that is communicatively connected to an elevator drive unit. The user interface allows the manual entry of each separate parameter. The parameters may be superficially checked for range errors while entry by the user interface, but there is no actual automatic checking regarding the elevator machinery actually installed. The parameters to be entered are read by the person performing the installation from such sources as the nameplate of the electrical motor.
The configuring of the elevator drive is a process that requires precision and takes time. Configuration errors may cause damage to the elevator when the elevator is tested following the configuration. Configuration may take, for example, one whole day for a person performing the installation.
Therefore, it would be beneficial if elevator drive parameters could be automatically determined so that a need for manual parameter entry would be eliminated.